Sample cups have to be hermetically closed preferably with a screwable cap in order to ensure that the sample contained therein cannot be contaminated by external agents and also in order to protect laboratory staff from the risk of being contaminated by a pathological sample which may be contained in the sample cup. This applies in general to sample cups used for clinical chemistry tests, and in particular to sample cups used in methods for isolating a nucleic acid sample from cell material.
According to the prior art the cap of such a sample cup has to be removed and replaced manually with great care in order to allow pipetting operations, e.g. for transferring a portion of a biological sample contained in a primary sample tube into the sample cup, before a method for isolating a nucleic acid sample from cell material is carried out on a sample contained in a sample cup; or for transferring a nucleic acid sample isolated by such a method into the sample cup.
The above mentioned manual removal and replacement of the screwable cap of sample cups is time consuming and is not compatible with the increasing need for automatic handling of sample cups in modern automatic sample cup handling apparatuses. There is therefore a need to automate the removal and replacement of the screwable caps.
There is moreover a need to transport individual sample cups closed with their respective screwable cap to different positions within the sample cup handling apparatus, e.g. in order to perform different steps of a method for isolating a nucleic acid sample from cell material.
It is therefore an object of the invention to provide an apparatus and a method and sample cups which are suitable for satisfying the above mentioned needs.
The invention concerns an apparatus for automatically handling sample cups closed with a screwable cap in a system wherein portions of biological samples contained in primary sample tubes have to be automatically pipetted into and from said sample cups.
The invention further concerns a method for automatically handling sample cups closed with a screwable cap in a system wherein portions of biological samples contained in primary sample tubes have to be automatically pipetted into and from said sample cups.
The invention further concerns a sample cup closed with a screwable cap which is adapted to be used in an apparatus and in a method according to the invention.
The invention concerns in particular an apparatus, a method and a sample cup of the above mentioned types which is suitable in particular for handling sample cups used in a method for isolating a nucleic acid sample from cell material.
According to a first aspect of the invention the aims of the invention are attained with an apparatus comprising a transportable gripper which includes a rotatable gripper tool adapted to enter and engage with a recess of said cap to form a connection which can be locked by rotating the gripper tool in a first sense with respect to said sample cup, and which can be unlocked by rotating the gripper tool with respect to said sample cup in a second sense opposite to the first.
According to a second aspect of the invention the aims of the invention are attained with an apparatus comprising
a) a sample cup holder having a plurality of chambers, each of which is adapted to receive and hold the lower part of a sample cup while preventing rotation thereof,
b) a plurality of sample cups, each of which is closed with a removable screwable cap and the lower part of which is inserted in one of said chambers of the sample cup holder, the outer wall of said cup having a zone the shape of which is adapted to cooperate with a corresponding zone of the inner surface of the chamber of the sample cup holder to prevent rotation of the sample cup inserted in said chamber,
said screwable cap having a recess located in the top and central part of the cap, said recess comprising a slot which extends along the length axis of the sample cup and which ends in two annular channel segments which extend in opposite angular directions with respect to the length axis of the sample cup,
c) a gripper movable in three orthogonal directions by a transport device, said gripper comprising a rotatable gripper tool which has an end part having a shape and dimensions which match the shape and dimensions of the recess of the cap in such a way that the end part of the gripper tool can enter through the slot of the cap""s recess and by rotation enter into and engage the annular channel segments of said recess,
d) a transport device for moving said gripper in said three orthogonal directions and for positioning and rotating said gripper tool to a predetermined angle within said recess of the cap of a sample cup.
According to a third aspect of the invention the aims of the invention are attained with a method for automatically handling sample cups closed with a screwable cap in a system wherein portions of biological samples contained in primary sample tubes have to be automatically pipetted into and from said sample cups, said method comprising transporting a sample cup
by means of a transportable gripper which includes a rotatable gripper tool adapted to enter a recess of said cap, said transporting being effected
by positioning said gripper tool in said recess,
by rotating said gripper tool within said recess with respect to said sample cup until it engages and locks into said recess, and
by transporting the gripper and thereby the sample cup from a first position to a second position.
According to a fourth aspect of the invention the aim of the invention is attained with a method for automatically handling sample cups closed with a screwable cap in a system wherein portions of biological samples contained in primary sample tubes have to be automatically pipetted into and from said sample cups, said method comprising
removing the cap of a sample cup by means of a transportable gripper which includes a rotatable gripper tool adapted to enter a recess of said cap,
said removing being effected
by positioning said gripper tool in said recess, and
by rotating said gripper tool within said recess in a first sense with respect to said sample cup, thereby unscrewing the cap and removing it from the sample cup.
According to a fifth aspect of the invention the aim of the invention is attained with a method for automatically handling sample cups closed with a screwable cap in a system wherein portions of biological samples contained in primary sample tubes have to be automatically pipetted into and from said sample cups, said method comprising replacing the cap of a sample cup by means of a transportable gripper which includes a rotatable gripper tool adapted to enter a recess of said cap, said replacing being effected
by positioning said gripper tool in said recess, and
by rotating said gripper tool within said recess in a second sense with respect to said sample cup, said second sense being opposite to said first sense, thereby screwing the cap and replacing it on the sample cup.
According to a sixth aspect of the invention a sample cup suitable to be used with an apparatus according to the invention is characterized in that it comprises a removable screwable cap which has a recess located in the top and central part of the cap, said recess comprising a slot which extends along the length axis of the sample cup and which ends in two annual channel segments which extend in opposite angular directions with respect to the length axis of the sample cup, and an outer wall having a zone adapted to cooperate with a corresponding zone of the inner surface of a chamber of a sample cup holder in order to prevent rotation of the sample cup when the lower part thereof is inserted in that chamber.
The main advantage of the apparatus, method and sample cup according to the invention is that they provide very simple and relatively inexpensive means for automatically opening, closing and transporting sample cups.
Exemplified embodiments of apparatus, method and sample cup according to the invention are described below with reference to the accompanying drawings.